JP3052370B2 - Biological image data collection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a biological image data collection device such as a gamma camera.

[Prior art]

When collecting image data of a living body using a gamma camera or the like, data may be collected in synchronization with the movement of the heart, and an image may be obtained at each time phase of the heart motion cycle. Conventionally, when performing such ECG-synchronized data collection, an electrocardiograph is used to measure an electrocardiogram, and based on the R-wave of the waveform, data is collected at each time elapsed from the time when the R-wave is generated. It is carried out. That is, when setting to obtain images (n images) in n time phases, the reference time interval between R waves is divided into n equal parts, and each time interval is set as a sampling time of each image data. The image data obtained at each sampling time is stored in a separate memory to create n images.

[Problems to be solved by the invention]

However, the movement of the human heart is not very accurate, and the cycle of movement of the heart is not always constant. Therefore, the actual R-wave intervals vary with respect to the reference R-wave intervals, and it is particularly difficult to divide the reference intervals equally, determine the sampling time of each image data, and sort the data to be stored in each memory. In the latter half of the cycle, there is a problem that the correspondence between the time phase of the heart motion and the sampling time varies, and an accurate reconstructed image cannot be obtained. SUMMARY OF THE INVENTION It is an object of the present invention to provide a living body image data collecting apparatus capable of collecting living body image data accurately in correspondence with each time phase of the heart even if the cycle of the movement of the heart fluctuates.

[Means for Solving the Problems]

In order to achieve the above object, in the biological image data collecting apparatus according to the present invention, for each incident radiation, a means for detecting biological image data representing an incident position, a means for detecting a motion of a heart, Means for storing biological image data representing a radiation incident position together with elapsed time information from a reference time phase of the movement of the heart when it is detected,
Means for measuring an interval between each reference time phase of the heart motion and dividing the interval by a set ratio to determine each sampling time; image storage means for at least the number of sampling times described above; By reading out the image data together with the elapsed time information and distributing the elapsed time information to any one of the image storage units depending on which sampling time the sampling time is, the image data is collected in each image storage unit, and the image data is collected in each image storage unit. Means for reconstructing an image for each sampling time.

[Action]

Each time radiation enters, its incident position is detected,
Biological image data representing the incident position is sequentially obtained temporally for each incident. On the other hand, the motion of the heart is detected, and the elapsed time from the reference time phase is measured for each cycle.
Each time the above image data (incident position signal) is obtained, it is stored. At that time, information on the elapsed time from the reference time phase is also stored. The intervals between the reference time phases are also measured for each cycle, and the intervals for each cycle are divided by a set ratio. Each of the divided times becomes each sampling time, and the number thereof is determined. Read the stored image data (incident position signal),
Distribute to each image storage means. At this time, the elapsed time information is read out together with the image data (incident position signal), and it is determined which image storage means is to be allocated according to which sampling time the elapsed time information enters. By this distribution, the image data (incident position signal) is collected in each image storage means, and the image data (incident position signal) is integrated in each image storage means, thereby reconstructing an image. . Therefore, an image for each sampling time is reconstructed in each image storage means, but the relationship between the sampling time and the time phase of the heart motion is always constant, and therefore, the heartbeat cycle varies. Even in this case, the image of each time phase can be reconstructed accurately. Instead of the completed image, the image data (incident position signal) itself, which is the pixel of the image, is sorted and integrated according to the sampling time to be entered, and the image is reconstructed. Is exactly the image within each sampling time. For example, if a sampling time is defined as a ratio of half the interval between the reference phases of the heart movement, the sampling time will always be exactly half the time of the heart cycle, whether the heart cycle is long or short. Correspondence with is maintained accurately. Therefore, the image data (incident position signal) distributed to each image storage means and integrated for reconstructing an image always has the same time phase despite the fluctuation of the cardiac movement cycle, and the expansion of the heart -It is possible to obtain an image of good image quality completely synchronized with each phase of contraction.

【Example】

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, for example, biological image data from a gamma camera (not shown) (that is, a position signal indicating an incident position of radiation and an unblank signal) is temporarily transferred to one of the input buffers 2 and 3 via a switching circuit 1. Is stored. On the other hand, a heart radio signal from an electrocardiograph (not shown) is input to the R-wave detection circuit 5, and the R-wave of the heart radio wave is detected.
The switching circuit 1 is alternately switched every time the R-wave detection signal is generated. On the other hand, the switching circuit 4 connected to the output side of the input buffers 2 and 3 is alternately switched to a phase opposite to that of the switching circuit 1. If the switching circuit 1 is switched to the upper side by the first R-wave detection signal, the image data is stored in the input buffer 2 and the switching circuit 1 is switched to the lower side by the next R-wave detection signal. Is stored in the input buffer 3. As described above, the image data is stored in the input buffer 2 for each cycle of the heart motion using the R wave as the reference time phase.
3 are stored alternately. The R-wave detection signal is also sent to the time information adding circuit 10, where time information indicating the elapsed time from the R-wave is added to the input image data. That is, the time information adding circuit 10
Measures the elapsed time from the R wave, and adds elapsed time information at the input timing of the unblank signal to the image data. Therefore, elapsed time information is stored in the input buffers 2 and 3 in the list mode together with the image data (position signal). Thus, the storage of the image data and the elapsed time information is 2
This is performed alternately in each of the input buffers 2 and 3 for each cardiac cycle. Image data and elapsed time information are read from the input buffers that are not stored and sent to the distribution circuit 6. The distribution circuit 6 distributes these image data to one of the n image memories 81 to 8n based on the elapsed time information. Further, the image data and the elapsed time information read from the input buffers 2 and 3 are simultaneously sent to the storage device 9 such as a hard disk in the list mode and stored therein. The distribution circuit 6 is controlled by a control circuit 7. An R wave detection signal from the R wave detection circuit 5 is sent to the control circuit 7, and the control circuit 7 measures a time interval between R waves. Then, the time interval is divided at an arbitrarily set ratio as shown in FIG. 2, for example, at a ratio of 1 / n. The n time zones (time zones demarcated by dotted lines in FIG. 2) obtained by the division become sampling times for collecting n images of each time phase. The information on each sampling time is stored in the control circuit 7.
The distribution circuit 6 determines which sampling time the image data falls into based on the elapsed time information combined with the image data, and the image memories 81 to 81 corresponding to the sampling time. Send image data to any of 8n. Therefore, in this embodiment, as shown in FIG. 2, the actual R-wave interval is divided into n equal parts for each period, and the image data generated in each time zone obtained by the equal division is stored in the corresponding image memory 81. ~ 8n will be collected and go. Therefore, even if the R wave interval becomes longer or shorter, image data in the same time phase is always accumulated in each of the image memories 81 to 8n. As a result, the image quality of each image reconstructed in each of the image memories 81 to 8n is improved. At the same time, since each image is created only by completely ECG-synchronized image data, it is accurate enough to withstand quantitative evaluation. Therefore, these images have ROI (Region of Interest)
Is set, and a change curve of the count number in the ROI is obtained, for example, a change in volume of a ventricle or the like can be accurately determined, and diagnostic performance can be improved. Further, since the image data and the elapsed time information are stored in the storage device 9 in the list mode, the storage device 9 can be reproduced later and the image analysis can be performed in the list mode.

【The invention's effect】

ADVANTAGE OF THE INVENTION According to the biological image data collection apparatus of this invention, the biological image data completely synchronized with each phase of the expansion and contraction of the heart can be collected even if the motion cycle of the heart fluctuates. Image quality can be improved. In addition, since each ECG-synchronized image is completely synchronized with each time phase of the heart's motion cycle, the accuracy of quantitative measurement is improved, and diagnostic performance can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining the operation. 1, 4,... Switching circuit,
2, 3 ... input buffer, 5 ... R wave detection circuit, 6 ...
Distribution circuit, 7 ... Control circuit, 81 to 8n ... Image memory, 9 ... Storage device, 10 ... Time information addition circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01T 1/161 G01T 1/164

Claims (1)

(57) [Claims] 1. A means for detecting biological image data representing an incident position of radiation every time a radiation is incident; a means for detecting movement of a heart; and detecting the biological image data representing each radiation incident position described above. Means for storing the time of the heart motion together with the elapsed time from the reference time phase, and measuring the intervals between the reference time phases of the heart motion and dividing the intervals by a set ratio to determine each sampling time Means, image storage means for at least the number of sampling times described above, and the stored image data is read out together with elapsed time information, and any one of the image storage means depends on which sampling time the elapsed time information falls into. By distributing, the image data is collected in each image storage unit, and the image for each sampling time is reconstructed in each image storage unit. Biological image data acquisition apparatus characterized by comprising means for.